I am not sure that I am 100% following, you say the trigger can happen every 0.01 - 1 second, this is between 10ms and 1 second, is this what you are saying? So is this what you mean by your detector response time?

In any case the 2204 will probably have a trigger re-arm time between captures of approximately 70ms depending on the computer the spec and resources on your computer.
The question is how many of these waveforms do you want to capture and how often do quick do you want to sample?

Yes, the trigger is between 10ms and 1 second. I Did a mistake before detector response time (repetiotion rate).

The standard working conditions of my apparatus are: a samplig rate of 50 KS/sec with an accumulation time (interval between trigger pulses) of 100 millisecond, so I have more or less 5 KS each waveform. We would like to capture waveforms int the range of 10-100.

What is the trigger re-arm time (about 70 millisecond or 70 microsecond)? Is the buffer memory (8kS) refreshed each trigger pulse?

Hi the trigger re-arm time of the 2204 is approximately 70 milliseconds on average (depending on PC and overheads).

Looking at your application the 2204 will not be be sufficient what you really need is a device that has larger memory and has a rapid block mode capture.

To explain further you will need to capture your data in block mode, normally the trigger re-arm time is too slow as it has to transfer each capture to the PC , however with a device that has rapid block mode the trigger re-arm time reduces to 1 or 2us depending on the device you choose. It does this by storing all the captures on the memory and then transferring it to the PC when the specified number of captures has finished ( as opposed to transferring each capture to the PC). For this to work in your application you will need a device that cans store more than 500k Samples, as you want 5k samples per waveform and you have 100 captures.

This brings you into the 3000 range, the 3204A has 4MS of memory and the 3204B has 8MS, any of these will be more than sufficient for your application. Just to let you know the difference between the A and B, apart from the memory the B model has an Arbitrary Waveform Generator which allows you to create your own waveforms rather than use a set of standard signals.